Sash balance



oct.' 21, 1941.

A. .1. ROSENTRETER 2,260,056.

sAsH BALANCE Filed Dec. 9, 1940(l Patented Oct. 21, 194.1

Na e. orreraiienvf Neiygfgri Application December 9, 19i9 rserial No.

W ottimal (oiriaisv) .:This invention lrelates to -a sash balancer-.with particular -vreference to. thev style off: constructionfthat employs a spring tension element; and it'hasffor its object to provide simple and practicali means =of yeconomical construction for llocking the spring element .infpredetermined posi.- tion after it is tensioned orV Wound. at; theffactory,` such locking means being releasedgautoe. maticallyvafter the .device is installedin afsash inoperative position upon the raising or .low'erf ing of the sash,.thus .assuring .underI operating conditions the tension given Athe.springs-'when the structure is made and assembled at the factory.-` 'i 12:' .if Devices have been heretofore proposed for. the. pretensioning ofi-springs in sash ybalances of this general character, but insuch instances, the usual-procedure has been for the Workman who installs ythesash balance to remove alooking instrumentality after-the parts a-re in operative. relation,.-and the objections to thisy arrangement i's that it-frequently happens that the removal of. the locking A-device vis neglected or.Y forgotten', resultingv in -the'inoperativeness of Athe `balance and dissatisfaction .with the mechanism;VV 4f To overcome this, it is proposedaccording'to the present .invention to Aprovide a spring vsash balance ywith `a locking device that is. arranged in lockingposition by the factory assembler after the spring has been Wound to the ddesiredfextent, and 'remains in suchv locking position until the device is installed'and ready for operation, whereupon movement of the vsash-automatically displaces the locking member,v either by Agravity or otherwise after it is released, and thereafterV the sash balancecontinues to operateunder the predetermined spring tension, there being-no further `function of the locking instrumentality unless it becomes necessary y to remove ..thef balance from the sash and again-wind vthe spring'.-

' spiral .bar andrspring and for mountingt-he Spring. and spiral bar upon suitable supporting platesY desovini-fiori a.vherrerrati` 1 aocornpany-ing-y drawing-fthe inovelfvfeatures fbeing sistse,infgfthegfonstructiona fand@ arrangements-of. parts that wil-lfappear iclearly trom-fthe following e conjunction flwi-thfthe Inthe drawing e Fig. 1 is a view in fro tcelevat-lon,

a in section, :illustrati-ng a-lpreferred-fernbodiment 1. its-upper @relookingpositionffholding the spiral bar.Av Withethe lspring-underq,tension: i Eiga 3. is .aasimi-larayiew showingrthef.locking. memberin laweredt position, withl the spiral bar anfoLspr-ing-freleased; 'lFigstis a horizontal sectional view on the OfsEigs ,2;j2rl1 l 'F il '"2'- A Eigvr i5 `;.isan perspective'. f'view-4 of the upper sup-.-T porting lplateauponwvh-ichithe spring and spiral member are mounted, and?. 1.', l A

Y Figf .fis a perspective view-,ot ,=the.iflowen astening .platelin-.whioh Ithe` spring fand; -spiral member are :journalledatftheir loweraendsff-.; ag @t f Y liheisubjectrfmatter 5otMtl-iisly applicationsisg'i'n theenatureof anzimproyement :on :the construc- 1"940QServials No. 345.5489; patent.=issu1edfiFebruary 4, 194 1,M No. 2,230,5163, f and p referringfmores pare' Y ticularly'mo. the drawing-1in whiohflikeff .reference numeralsrefer tolti-1o,y same :parts throughout-:the iews, Ifadesignates ai wndowj: sash slideA able .fvvith-m.7 ayfijame, and-f mortised'- at? itsA edges toA receive' the mechanismA to :be 4described. ?.Tne structurer1 Vincludes supporting.' meansg-inethe 'form' of. @fastening plate-=3, that-isfrigidly :secured to` overlyingrthemortised portion in the side of;l the sash,saicvtouter end including-iagdepending pori-5 tion'eand a horizontal supporting j platejf thatV is 4slotted.at Gato^ receives. and-l` support I the -con' 1 trolling VspringandY t rotatable.; spiral member carried t-hlerleor-i,5.,iwvhile 1f-.designates .upstanding lateralfiianges .for apurpose that will 'appear presently. livery@ "rf-.'fmr'cz 4 -l l". 1 "11 "wi, The rotatable A+.n1ernber consists of 1a f-etwisted orivspiralabar 8-:Which.-i-is.trotatab1y .fmou-ntedein 't relation to the supporting means already described, and so associated with a coil spring 9 as to place the same under tension when the spiral bar is moved endwise and thereby rotated upon movement of the sash. Preferably this relationship is effected by mounting the spiral bar 8 upon the coil spring 9 as shown, by providing a right-angled or lateral portion or lug I at the upper end of the spiral bar, said lug I0 being provided with an opening through which the spring 9 extends, the spring thus .affording a bearing for the rotatable spiral bar.

Beneath the lug I0, the coil spring 9 is twisted around the spiral bar 8 following the convolutions thereof, and at the lower end of the bar, the coil spring is bent laterally to afford an offset terminal portion II that receives a' lug I2 at the end of the spiral bar 8, thus holding the lower ends of the spiral bar and spring in rigid relationship while permitting relative turning plate I8 having a curved edge I'I engaging a corresponding groove in the mortised portion of the sash. The bearing plate I6 is provided with an opening -I8 that receives'the-terrninal portion II of the coil spring and serves as a centering bearing therefor, the bottom of said terminal portion` II and thefbottom of the lug I2 ofthe spiral-bar being somewhat above and in spaced relation to the fastening plate I3@ The coilspring 9 has attached' to its upper end anut or hollow squared head 2| to which the spring may be rigidly attached inany desirable manner as by aY-,pin 22 driven into the coil spring .and holding the latter firmly between it andthe surrounding surface of the vsquared head 2l. Theentire .assembly` including the spiral bar and spring is mounted upon the supporting plate. 5 by sliding the spring laterally through the slot 6 with the nut-or squared head 2i located above the supportinglplate 5, and between the upstanding lugs'l which hold the squared head 2| inposition and prevent its r0- tation when therspiral bar is rotated and the spring thereby twisted.

' The 'spiral bar is adapted to be rotated in any suitable fashion when the sash is moved, and

this may be accomplished conveniently by a platev aaedoee ation after installation, it is desirable to turn the spiral bar and thereby tension the spring to a predetermined extent at the factory when the structure is made and assembled and to maintain the spring by suitable locking means under such predetermined tension imparted to it at the factory until it is completely installed and ready for use. According to the present invention, after such installation, upon movement of the sash the locking means by which the spring has been held in its pretensioned condition is automatically released.

This may be accomplished in various ways and preferably, as shown in the present embodiment, by a locking member that is movably mounted upon the spiral oar and actuated to its unlocking position by gravity. To accomplish this, there is preferably employed a locking member in the form of a slidable keeper 26 having flanges 21 embracing the straight portion at the upper end of the spiral b-ar 8 and permitting the keeper 26 torslde thereon, while 28 is a locking portion movable through-the slot 6 in the supporting'plate 5 and having a nose 29 adapted to engage over the upper surface of said supporting plate 5 adjacent to the slot 6 to hold thelocking member in its uppermost or locking position,V as shown in Fig. 2. 3i is a cam surface on the locking portion that is engaged by the edge of slot 6, when the spiral bar is turned, and positively moves the keeper downwardly to release the parts if the action of gravity is not sufficient for the purpose.

It will be understood that whenreleased, the locking member moves downwardly until it Y reaches the twisted or spiral portion of the bar causing the latter tobe rotated in one directionor the other as the sash is raised or lowered;

Thus as the sash and mechanism mounted thereon moves upwardly or downwardly, the spiral bar 8 is rotated by the lugs 24 on the stationary plate 23, and since the spiral bar isflxed4 rotate the latter to its initial position, holds the bar in frictional engagement with they lugs 24 with'sufficient force to retain the window in any position to which' it is moved, and there is always` sufficient tensionf of the spring to hold the sash at any given point in its vertical travel.

' rnofde'r to facilitate the installation ofsuch a yspring balance-and -to insuredts proper-opermains where it is retained in its lowered or unlocking position illustrated in Fig. 3, and the spiral bar can be rotated and the spring tensioned to any extent desired, while the locking member rein such lowered position. When the spring has been tensioned to the proper degree, as determined by factory standards, the spiral member is turned further until the locking member is opposite the slot 6, as shown in Fig. 3, whereupon the operator manually slides the keeper upwardly until the portion 28 and nose 28 are within the slot 6 and above the supporting plate porti-on 5. Then upon releasing the spiral bar, the nose 29 of the locking portion engages the adjacent surface of the supporting plate 5, as shown in Fig. 2, and holds the spiral bar in such position with the spring under the tension already imparted to it.

Theparts remain in this position, and there is no necessity for the workman who installs the balance to do anything about tensioning the springjsince when the parts are secured in operative position, 'upon raising or lowering the sash from its initial position, additional tension is placed on the spring and the spiral bar is turned slightly and sufficientlyA to move the locking member from the position of Fig. 2 slightly to the right where the nose 29 of the locking portion is free. Thereupon the locking member falls by gravity, or is actuated by the engagement of cam surface 3l with the edge of the slot E in advance of its movement, to the position shown in Fig. 3,V and hasy no further function to perform' while the balance remains installed and in operation. The spring then continues to functionv under the tension established lfor it at the factory.

'Itwill beunderstoodfthat if it becomes necessaryftotremove the balance, to repair or replace any of the parts, the spring is again tensioned and the loclung member placed in locking position to hold the spiral bar and spring until after th'e device is again secured to the sash in operative relationship, whereupon the locking member is automatically released upon movement of the sash.

While the invention has been described with reference to the structural details disclosed, it is not confined to this particular embodiment, and the application is intended to cover any modifications or departures coming within the purposes of the improvement and the scope of the following claims.

I claim:

1. A sash balance construction comprising a spiral bar vertically and rotatably positionable on a sash, a coil spring connected to said rotatable spiral bar and controlling its movement, and locking means positionable to engage the rotatable spiral bar with a stationary part and hold the spring and rotatable spiral bar in predetermined relation, said locking means being slidable on the spiral bar, and means acting automatically to engage and move the locking means on the spiral bar to free the rotatable spiral bar and spring upon movement of the sash to which the parts are attached.

2. A sash balance construction comprising a spiral bar vertically and rotatably positionable on a sash, a coil spring connected to said rotatable spiral bar and controlling its movement, locking means positionable to engage the spiral bar with a stationary part and hold the spring and spiral bar in predetermined relation, said f locking means being slidable on the spiral bar and movable downwardly automatically to unlocking position when the sash to which the parts are attached is moved, and means acting automatically to engage and move the locking means on the spiral bar to free the rotatable spiral bar and spring upon movement of the sash.

3. A sash balance construction comprising supporting means, a spiral bar rotatably suspended from the supporting means, a coil spring which lies lengthwise along the spiral -bar bodily, conforming to the convolutions thereof and having its upper end secured in fixed relation to the supporting means and its lower end fixed to said spiral bar, an actuator positionable in relatively fixed relation for engagement with the' spiral bar and acting to turn the latter when relative endwise movement is effected between the spiral bar and actuator, locking means movably mounted at the upper end of the spiral bar and engageable with a portion of the supporting means for holding the spiral bar and spring under predetermined tension, said locking means being movable downwardly and automatically released from locking position when the spiral bar is turned by movement of the sash to which it is attached, and means acting automatically to engage and move the locking means on the spiral bar to free the rotatable spiral bar and spring upon movement of the sash.

4. A sash balance construction comprising supporting means, a spiral bar rotatably suspended from the supporting means, a coil spring which lies lengthwise along the said spiral bar bodily conforming to the convolutions thereof and having its upper end fixed to the supporting means and its lower end fixed to the adjacent end of said spiral bar, an actuator positionable in relatively xed relation for engagement withv said spiral bar and acting to effect rotation thereof upon relative endwise movement between the` spiral bar and the actuator, locking means slidably mounted at the upper end of the spiral bar and engageable when in its uppermost position with a portion of said supporting means for holding the spiral bar and spring under predetermined tension, said locking means being automatically movable downwardly to unlocking position when the spiral bar is rotated upon movement of the sash to which it is attached, and means acting automatically to engage and move the locking means on the spiral bar to free the rotatable spiral bar and spring upon movement of the sash.

5. A sash balance construction comprising supporting means including a plate slotted at one edge and having upstanding flanges adjacent to said slot, a coil spring extending through said slot and flxedly carrying a head located on said plate between said upstanding flanges and held against rotation thereby, a spiral bar having a laterally extending end portion located under said plate and journalled on said spring, the portion of the spring below said end portion of the bar lying lengthwise along the spiral bar bodily conforming to the convolutions thereof and having a terminal portion at its lower end offset from the body of the spring, a lug at the lower end of the spiral bar engaging said terminal portion of the spring, an actuator positionable in relatively fixed relationship to the spiral bar and acting to effect rotation thereof when relative endwise movement is effected between the spiral bar and the actuator, a locking member slidably mounted on said spiral bar and having a locking portion movable through the slot in said plate and engageable with the latter to hold the spiral bar against rotation, the locking member being downwardly movable automatically upon the spiral bar to unlocking position when the spiral bar is turned upon vertical movement of the sash to which it is secured, and means acting automatically to engage and move the locking member on the spiral bar to free the rotatable spiral bar and spring upon movement of the sash. f ALBERT J. ROSENTRETER. 

